Firefox automation using Spider

As of Spider 0.0.2.4, Spider can load chrome urls which can be used to load the browser chrome
as a page which can be scripted.

As a first test attempt at automating Firefox, I've tried to perform a series of actions such as opening menus, making selections from menus,
and loading pages using keyboard short cuts and user generated KeyEvents. The results are promising but have limitations
due to the fact that the user generated KeyEvents are not trusted and the need to keep track of the objects which currently
have focus. The userhook script is a kludge, but illustrates the attempt.

To run the automation yourself, first install Spider 0.0.2.4, then
either:

The attempts to navigate to a new page using the keyboard fail. I think this is due to the
untrusted nature of the user create KeyEvents.

The Error Console is successfully opened when run in the browser if you grant permission to spider
to open popup windows (?!) but fails to open when run as a chrome application.

The script needs to do a better job of tracking the XUL element with the focus so that the key events can
be properly dispatched. Note that actions which open OS native widgets (such as file pickers) or that open
other applications (such an Email application), are not controllable using this technique.